* {
  margin: 0;
  padding: 0;
}
html,
body {
  width: 100%;
  position: relative;
}
a {
  text-decoration: none;
  color: gray;
}
nav {
  width: 100%;
  height: 80px;
  background-color: white;
  position: fixed;
  left: 0;
  top: 0;
  z-index: 999;
}
nav img {
  float: left;
  margin: 30px 0 0 100px;
}
nav ul {
  width: 500px;
  display: flex;
  list-style: none;
  float: right;
  justify-content: space-around;
  line-height: 80px;
  margin-right: 100px;
}
nav li {
  font-size: 20px;
  color: grey;
}

section {
  width: 100%;
  height: 300px;
  text-align: center;
  font-size: 36px;
  line-height: 100px;
  margin-top: 100px;
}
input {
  width: 600px;
  height: 50px;
  text-align: center;
}

h1 {
  text-align: center;
}

article {
  width: 1100px;
  height: 500px;
  margin: 50px auto;
  display: flex;
  flex-wrap: wrap;
  justify-content: space-around;
}
article a {
  display: block;
  width: 350px;
  height: 200px;
  text-align: center;
  font-size: 18px;
  display: flex;
  /* cursor: pointer; */
  flex-direction: column;
  justify-content: space-around;
  align-items: center;
  background-color: rgb(250, 250, 250);
}
article img {
  width: 100px;
  height: 100px;
  text-align: center;
}

aside {
  width: 1100px;
  margin: 50px auto;
  display: flex;
  justify-content: space-around;

  text-align: center;
  vertical-align: middle;
  font-size: 16px;
}
aside p {
  width: 250px;
  height: 70px;
  font-size: 18px;
  line-height: 50px;
  position: relative;
}
aside img {
  width: 30px;
  height: 30px;
  position: absolute;
  left: 50px;
  top: 10px;
}

footer {
  width: 1200px;
  height: 300px;
  margin: auto;
  margin-top: 50px;
  font-weight: bolder;  
  padding-top: 50px;  
  position: relative;
  margin-top: 50px;
  background-color: rgb(248,249,252);
}
footer .left {
  width: 400px;
  height: 300px;
  float: left;
  display: flex;

  flex-direction: column;
  line-height: 40px;
}
footer .right {
  float: left;
  display: flex;
  flex-direction: column;
  width: 400px;
  height: 300px;
  line-height: 40px;

}
footer p {
  font-size: 20px;
}
footer a {
  font-size: 18px;
}
footer a:hover {
  color: rgb(86, 208, 133);
}
footer span {
  color: #cecece;
  position: absolute;
  left: 0;
  bottom: 50px;
}
